O2 custom power

I will buy an O2 pcb board and will build custom case. It will be kind of desktop version of O2. I only have experiance from a cmoy. Have couple of quastions about building a new O2.

How can i make an O2 to take power direct from AC? I think transformator can fit in the battery section which will be empity(we take power from ac). But not shure how to connect. And which transformator? 20, 25, 30? Quality of this part effects sound?

I also want a 6.3mm balanced output, rca inputs. Also don't know how to connect.

Do you have any recommendations to changing parts to have better sound? Like better or higher capacitors? Better connectors?

I will buy an O2 pcb board and will build custom case. It will be kind of desktop version of O2. I only have experiance from a cmoy. Have couple of quastions about building a new O2.

How can i make an O2 to take power direct from AC? I think transformator can fit in the battery section which will be empity(we take power from ac). But not shure how to connect. And which transformator? 20, 25, 30? Quality of this part effects sound?

I also want a 6.3mm balanced output, rca inputs. Also don't know how to connect.

Do you have any recommendations to changing parts to have better sound? Like better or higher capacitors? Better connectors?

I believe other people have experimented with a custom case for O2.. so you can also. However, you probably should not connect the AC power line anywhere inside that case. There would be a risk of shock or fire, and not much advantage. Plus, you need a larger case. It is easier and simpler to use a small wall-wart.

IMO, the O2 is as good as it needs to be. If you "improve" it, you no longer have an O2, just something that might seem over-engineered.

There's nothing that says you can't put a transformer inside a case along with an O2 PCB, if you want to build one that way. However, I believe the PCB is limited to a 20V transformer input because of the +or- 12VDC regulators. You'd be burning off too much voltage for the regulators to support without heat sinks and I don't think it was designed that way on the PCB.

Likewise, there's no reason you can't install different connectors (RCA or a full-size headphone jack) if you wire them directly to the existing pads on the PCB and case-mount them. The "balanced" output would be pointless, however, since the amp is not balanced. You'd be better off making up a convertor connector for the headphone cable.

And as someone who is getting into DIY like you are, my advice would be to not do it. If you are posting with that many questions, you don't understand enough about the power circuit to mess around with it. Really dig into the material until you understand enough to make the part selection and modifications yourself. Then come here or go to DIYaudio.com for confirmation and support.

I am building a Sigma 11 not because I really need it (although people say it will help my HDP sound better), but because I really want to understand how power circuits work.

More specifically, many people, including myself have altered the input and output configuration to better suit desktop use. It is easily done.